Reapply "Do not directly load smi constants larger than a 16 bit..."

runtime/vm/assembler_arm.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ASSEMBLER_ARM_H_
 #define VM_ASSEMBLER_ARM_H_
 
 #ifndef VM_ASSEMBLER_H_
 #error Do not include assembler_arm.h directly; use assembler.h instead.
 #endif
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/constants_arm.h"
+#include "vm/object.h"
 #include "vm/simulator.h"
 
 namespace dart {
 
 // Forward declarations.
 class RuntimeEntry;
 
 class Label : public ValueObject {
  public:
   Label() : position_(0) { }
@@ skipping 701 matching lines @@
   // calls. Jump to 'failure' if the instance cannot be allocated here.
   // Allocated instance is returned in 'instance_reg'.
   // Only the tags field of the object is initialized.
   void TryAllocate(const Class& cls,
                    Label* failure,
                    Register instance_reg);
 
   // Emit data (e.g encoded instruction or immediate) in instruction stream.
   void Emit(int32_t value);
 
+  // On some other platforms, we draw a distinction between safe and unsafe
+  // smis.
+  static bool IsSafe(const Object& object) { return true; }
+  static bool IsSafeSmi(const Object& object) { return object.IsSmi(); }
+
  private:
   AssemblerBuffer buffer_;  // Contains position independent code.
   GrowableObjectArray& object_pool_;  // Objects and patchable jump targets.
   int32_t prologue_offset_;
 
   const bool use_far_branches_;
 
   int32_t AddObject(const Object& obj);
   int32_t AddExternalLabel(const ExternalLabel* label);
 
@@ skipping 122 matching lines @@
                                   Register value,
                                   Label* no_update);
 
   DISALLOW_ALLOCATION();
   DISALLOW_COPY_AND_ASSIGN(Assembler);
 };
 
 }  // namespace dart
 
 #endif  // VM_ASSEMBLER_ARM_H_